Prepping For-Print Art for Roll20

Types of Art in a Roll20 Product

(Examples of the Roll20 Tabletop breakdown of several pages from Paizo's "Absalom: City of Lost Omens")

The following are Roll20 Tabletop elements where images from your Content can be added:

• On a Page
  • What can be seen on the Tabletop is broken up into different scenes which are called Pages. These are created and organized from the Page Toolbar. Each Page has four layers (Map, GM, Token, and Light). GMs can see everything on every layer, while Players are limited to what they are allowed to see. Pages are where you would include battlemaps, landing pages, dashboards, world/city maps, and any other visual intended to be made visible to the Players for a long period of time.
• In the Journal Tab
  • Character Sheets: Character sheets, both PC or NPC, have a spot to include a Portrait (Avatar) as well as a place to link a Token graphic. It's not uncommon for Token art to be reused for the Character Portrait when a unique portrait is not viable or unavailable.
  • Handouts: Before any text is displayed, there is a placeholder for a single image. This is an ideal place for uploading images of action scenes, landscapes, monster images, and special inventory items. 
• In the Collections Tab
  • Custom Card Decks: If your product includes a Card Deck, you can add your card fronts and backs in Roll20 to create custom card decks. To stretch their functionality Card Decks can also be set up to include infinite cards so you can create custom Card Decks that represent tradable resources such as images of setting specific currency, storyteller points, poker chips, etc.
  • Rollable Tables: While Rollable Tables can be used for text-only randomized lists, you can also upload images as table entries. This allows you to create Token objects that have multiple "sides." These can be used to create custom dice faces, shapeshifting Monsters/NPC Tokens, or portions of map terrain that can change or move.

Roll20 Viable Image File Types

The acceptable image file formats for Roll20 are JPG, PNG, GIF (static or animated), and WEBM. What image type you should use depends on what you're using the image for. Do NOT use WEBP which are more prone to breaking.

Tokens
We recommend creating PNGs with an Alpha Channel for static Tokens to support transparency/translucency. For animated Tokens, we recommend using the WEBM file format if you need translucency as well as transparency in your animated graphic. Use the GIF file type if all you need is transparency in your animated Token.

Everything Else (Maps, Handout images, Character Portraits, etc.)
We recommend creating JPGs whenever possible. PNGs should only be used if transparency or translucency is required in the image. For animated assets, use GIFs or WEBM files.

Editing Images when you don’t have the Original Art Files

The ideal situation would be to have access to the original art files (ex Photoshop PSD file) for your artwork, with layers intact.

You can still work with flattened images or assets only available from the source PDF itself, but plan enough time for the required image editing and/or retouching needed to make them viable for the Roll20 Tabletop version. 

Pulling Art from a PDF

There is one caveat you want to consider if you have to go this route for pulling graphics—you’ll want to use a PDF that has been compiled for print rather than one intended to be web-friendly. The latter type intentionally downscales image quality during file size compression.

Photoshop and most image editing software have the ability to directly open or import PDF files. Typically this works with the program asking you to choose a single page from the book that will then rasterize into a single flattened image for you to work with.

When rasterizing a page from a PDF, you'll want to import it at a larger dimension than what you plan the final image to require. Keep these factors in mind when rasterizing a PDF Page:

• You can ignore what is being used for Image Resolution unless it’s using some absurdly large value. A PDF is likely using a native resolution between 100-200 PPI. This is fine to leave it as is.
• Make sure the Color Mode is set to “RGB” and not “CMYK”
• You will unlikely know how big the image dimensions will need to be at this stage, so increase the pixel height and width values generously here.
  • If you’re working with a 5-foot square-gridded battle map, you’re aiming to have a grid unit to have at least 70 pixels to work with. Make sure Proportions Constraints are locked down so you aren’t warping the image when adjusting the image's dimensions.
  • If you’re working with a piece of scenery, a dashboard, a landing page, or a world/town map that you plan to place on a Page, you’ll want the final image to be around 2000 pixels in either height or width (whichever dimension is the largest).
  • Images intended for Character Portraits will be resized to a maximum width cap of 250 pixels in a Character Sheet. Any rectangular dimension ratio is acceptable, but you might find that a 250 x 250 image works best here. If someone is emoting or "Speaking As the Character" with the included portrait art, a thumbnail version of that image will appear beside the text prompt.
  • The image dimensions for a Handout image can be any rectangular dimension ratio. When the image is clicked on the Handout, it will display in Lightbox mode centered and viewed at 100% scale if the image dimensions are smaller than the browser window. If it's larger than the browser window at 100%, it will be resized (keeping its aspect ratio) to fit within the confines of the browser window. Landscape formatted images will fill up more screen space when viewed on most monitors and displays.

Strip Out GM Labels From Images!

Map with GM Labels	Map with GM Labels Removed
A portion of a map from Paizo's Sundered Waves adventure showcasing examples of GM Labeling (highlighted in yellow) that would need stripping out for Roll20 Tabletop use.

In most cases, for-print maps are designed with the GM in mind. Guides such as location labels, area numbers, map keys, traps, and secret door locations are drawn directly on the map. These elements should almost never be visible to the Players and will require removal from the image. If you are fortunate to have a layered Photoshop file, these elements are often not baked onto the map artwork and can be simply turned off when exporting the final image. If they are flattened to the map art, you're going to need to retouch the image to remove their presence.

Export GM Map Labels and Secrets Separately

These GM elements should be saved as individual PNG files. These images will eventually be reassembled on the GM Layer in the Roll20 Tabletop. (This Tabletop layer is only visible to the game's GM.)

  Don't Save Your GM Labels as One Giant PNG Image

We do not recommend doing this since other Token content is often placed on the GM Layer alongside GM Labels (like hidden monsters and NPC Tokens). Those other Tokens might end up underneath and not selectable if the GM Labels are all compiled together as one large map overlay.